Rotary encoders are often used for determining the angular position of two machine parts rotatable relative to each other, and operate according to an inductive measuring principle, for example. In inductive rotary encoders, exciter windings and receiver windings are applied, for instance, in the form of printed conductors on a shared printed circuit board that is fixedly joined, e.g., to a stator of the rotary encoder. Centered opposite this printed circuit board at a defined axial distance is a further printed circuit board taking the form of a code element or preferably an annular code disk, on which in periodic intervals, electrically conductive and non-conductive areas are applied in alternation as graduation regions or graduation structures, and which is fixedly joined to the rotor of the rotary encoder. When an electric exciter field alternating in time is applied to the exciter windings, signals are generated in the receiver windings during the relative rotation between rotor and stator as a function of their relative position, thus, as a function of the relative angular position. These signals are then further processed in evaluation electronics.
Such rotary encoders are often used as measuring devices for electric drive systems, to determine the absolute angular position of corresponding drive shafts.
German Published Patent Application No. 10 2006 046 531 describes an inductively operating rotary encoder in which a mode economizing on current is able to be arranged using a special pulsing regime.